Ghostlights and Fireflies after Daz "fix"

Danny

Hi there :)

After Daz "fixed" the ghost lights I have problems with fireflies. Because I have to increase the light value a lot when reducing the opacity of a ghost light to 0.0000001 or something, the ghost lights become partially visible in the render again as fireflies. Example images below show this. in the left image a primative plane was user under the ceiling and at the right a mesh ghost light was used.

Is there any way after the update to solve this problems? I mean the use of ghost lights is that they are invisible. If they are not invisible anymore they have no use.

Richard Haseltine

You mean after nVidia fixed the interaction of opacity and emission.

Danny

Richard Haseltine said:

You mean after nVidia fixed the interaction of opacity and emission.

Sure. But Problem ia still the same.

Catherine3678ab

Even before the 'fix' that problem could occur, so I got into the habit of keeping the mesh light out of the camera's view ;-)

Danny

Catherine3678ab said:

Even before the 'fix' that problem could occur, so I got into the habit of keeping the mesh light out of the camera's view ;-)

Depended on the light value of the ghostlight. But it was way better than it is now. I have no problem increasing the light value of a ghost light, but the effect of it becoming visible kills it. 

Danny

I also noticed that the same scene with emissive lights renders much worse than with spot lights etc. That also wasn't the case before the update.

For example for the following scene I used mesh lights before. invisible ones before the update, now I moved them outside the visible scene.

(The mesh light version is a little brighter, but that does not change the amount of grain it has compared to the other one.)

(3 Point Lights)

(Mesh Light Emissive)

I rendered the same scene once with a 3 Point Lighting at the character and once with an emissive mesh light at the character.

Both renders are otherwise completely identical to setup, resolution, iterations...

I already used mesh lights on the same scene/location before and the results were much better, but that was before the update.

It looks like it got much harder for the engine to calculate the light.

Fishtales

Try changing the Nominal Luminance under the Firefly Filter. I keep mine at 1500 but there are occasions where I have to lower it to get rid of persistent Fireflies. Be aware though it can have an effect on how volumes are rendered.

Danny

Fishtales said:

Try changing the Nominal Luminance under the Firefly Filter. I keep mine at 1500 but there are occasions where I have to lower it to get rid of persistent Fireflies. Be aware though it can have an effect on how volumes are rendered.

Mine was at 0, which is the default value? 

I tried out some values now (0, 500, 1000, 1500) but the grain is the same. It just gets darker with a lower value (0 exluded).

Fishtales

I have tried a couple of my scenes made in 4.20 latest Beta with ghost lights and can't emulate your problem. If I have the product you are using in my content library you could attach the scene file here and I can have a look.